10. ROBOTICMANUFACTURING

SYSTEMSDESIGN AND APPL ICAT IONS OF INDUSTRIAL ROBOTSSABARIG IR IVASAN.RISBN 978-81-908268-0-8

10. ROBOTICMANUFACTURING

SYSTEMSDESIGN AND APPLICATIONS OF INDUSTRIAL ROBOTSSABARIGIRIVASAN.RISBN 978-81-908268-0-8

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Robotic Manufacturing Systems

1. Robots are designed to automate manufacturing operations that are monotonous and dangerous in nature.

2. The manufacturing cell that is serviced by one or more robots is known as robot work cell.

3. The robot work cell should have complete set of hardware, software and cell control system.

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Structure of a Robot Work cell

A robot work cell has the following equipments1. Robots2. Production machineries3. Supply conveyor4. Delivery conveyor5. Cell controller6. Communication peripherals7. Protective barriers (Perimeter guard)

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Structure of a Robot Work cellStructure of a Robot Work cell

M1

M2

M3

M1, M2, M3 – Production machines

Protectivebarrier

Robot

Control panel formanual override

Cell access door

Supplyconveyor

Deliveryconveyor

D E S I G N A N D A P P L I C A T I O N S O F I N D U S T R I A L R O B O T SS A B A R I G I R I V A S A N . R

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Structure of a Robot Work cell

Animation

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Classification of Robot Work cellBased on Number of Robots

1. Single robot work cella) Only one robot is employed to perform all

operations.b) Machine interference can occur.c) Interference is caused due to imbalance in machine

cycle and robot service times.2. Multiple robot work cell

a) More than one robot will be employed to perform all the required operation.

b) Cell control system is employed to avoid collision.

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Classification of Robot Work cellBased on the Position of Robots

1. Robot centered work cell.2. Inline robot work cell.

a) Intermittent part transferb) Continuous part transfer

3. Mobile robot work cella) Floor mounted rail systemb) Overhead rail system

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Robot Centered Work CellRobot Centered Work Cell

Machine 1

Machine 3

Machine 5

Machine 2 Machine 4

RobotSupply conveyor

Raw materials

Delivery conveyor

Finished products

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Robot Centered Work Cell

Animation

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Inline Robot Work CellInline Robot Work Cell

RobotWork piece

Moving production line

D E S I G N A N D A P P L I C A T I O N S O F I N D U S T R I A L R O B O T SS A B A R I G I R I V A S A N . R

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Inline Robot Work Cell

Animation

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Inline Robot Work Cell

Animation

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Robot Work Cell for Spot Welding(Inline work cell – Intermittent part transfer)

Robot Work Cell for Spot Welding(Inline work cell – Intermittent part transfer)

Robot Spot welding endeffector

Car frameConveyor

Robot

D E S I G N A N D A P P L I C A T I O N S O F I N D U S T R I A L R O B O T SS A B A R I G I R I V A S A N . R

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Mobile Robot Work Cell – FloorMounted Rail System

Mobile Robot Work CellFloor Mounted Rail System

Machine 1 Machine 2

Carriage Robot

Floor mounted rail

D E S I G N A N D A P P L I C A T I O N S O F I N D U S T R I A L R O B O T SS A B A R I G I R I V A S A N . R

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Mobile Robot Work Cell – FloorMounted Rail System

Animation

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Mobile Robot Work Cell – OverheadRail System

Mobile Robot Work CellOverhead Rail System

D E S I G N A N D A P P L I C A T I O N S O F I N D U S T R I A L R O B O T SS A B A R I G I R I V A S A N . R

Machine 1 Machine 2Supplyconveyor

Deliveryconveyor

Overhead rail RobotCarriage

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Mobile Robot Work Cell – OverheadRail System

Animation

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Safety Considerations1. Safety is of paramount importance in any

industrial operation.2. The robot should be protected from

damaging itself and injuring humans while in action.

3. Everything in the cell should be maintained well and checked for safe operation so that no mishap occurs.

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Potential Hazards for Safety 1. Oil leaks in hydraulic robots and pressure

loss in pneumatic robots.2. Broken power cables.3. Poor maintenance.4. Poor quality of components.5. Software errors.6. Uncoordinated robot motion with the

production machine.

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Potential Hazards for Safety

7. Careless attitude of workers.8. Unauthorized entry of workers into the

cell.9. Careless attitude of management.

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Protective Measures1. Providing multi tier security system.2. Intruder alarm and glowing sign boards

should be provided.3. The robot should be stopped on detecting

an intruder.4. Protective barriers like wire mesh or guard

railings should be provided.5. Robots should be clearly visible and

painted in bright colours.

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Protective Measures6. Cell access doors should get automatically

locked while the robot is in action.7. Control panel for manual override should

be provided.8. Emergency stop switch should be clearly

visible and should be within easy reach.9. Dormant state of the robot should be

indicated by visible light signals.

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Protective Measures10. Unwanted objects should not be left inside the

cell.11. High quality components should be used.12. Painting robots should be given proper

covering.13. Robot should be stopped if any of the sensor

fails.14. Adequate training and safety awareness

should be imparted to the workers.

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Economic Considerations1. Robots are expensive equipments hence

cost is an important factor to be considered while robotizing the production facility.

2. Robot costsa) Initial investmentb) Operating costc) Earnings and savingsd) Miscellaneous costs

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Cost Comparison1. Before robotizing, other production process

should be considered to arrive an optimal conclusion.

2. Earnings made for certain production volume should be compared with manual production and fixed automation.

3. Only when substantial cost benefits are realized it will be a profitable business.

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Cost Comparison ChartCost Comparison Chart

Cost perunit

Production volume

Graph plotted against logarithmicscale on both the axes.B1, B2, B3 – Break even points

B1 B2

B3Robotic production

Manual production

Fixed automation

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Cost EstimationTwo simple techniques for making estimates

of earnings to justify robotization are1. Payback period method2. Return on Investment method

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Payback Period Method1. The investor calculates the payback period to

recoup the money spent on robots.2. Payback period is the time in years required to

take back the money spent as investment and expenditure on robots.

3. Payback period is given as

4. The robot has salvage value after payback period.

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Return on Investment Method1. The investor calculates the rate of return

from the robotic operations.2. Rate of return is the percentage of investment

earned per year.

3. The actual rate of return should be greater than the expected rate of return only then the business will be profitable.

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Robot Selection1. A robot is selected by considering its

various operational parameters.2. The features of a robot required to do the

required operations are determined in advance using results of the study made by the Industrial Engineering department.

3. The robot should meet the required criteria so that it can perform all the operations effectively to which it is intended for.

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Robot Selection Criteria1. Precession – Accuracy, resolution and

repeatability.2. Speed.3. Payload.4. Type of drive system.5. Programming methods.6. Memory capacity.7. Number of Degrees of Freedom.

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Robot Selection Criteria8. Power interface.9. Communication interface.

10. Availability of standard endeffectors.11. Cost, the most important deciding factor.

End of the Presentation

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